Scanners love to add a blank final page, and contracts often carry pages you have no reason to forward. Taking pages out is the most common PDF edit there is.
It sounds like the same thing, but selecting the pages you want is far less error prone than deleting one at a time. You end up checking your work as you go, and there is no risk of losing a page you meant to keep because the numbering shifted under you.
Watch out for double sided scans. A scanner set to duplex will produce a blank page for the back of every single sided sheet, so a ten page document arrives as twenty. Removing the blanks halves the file size as well as the page count.
Your original is never modified. The tool produces a new file, so if you cut the wrong page you simply start again from the document you still have.
Yes. Select every page you want to keep and save them together in one go.
The page order stays as it was. Any numbers printed on the pages themselves are part of the image and do not change.
No. The pages are read and rewritten inside your browser.